[0001] The present invention relates to methods for preparing patterns for 3-dimensional
electric circuits.
[0002] Methods to prepare patterns for electric circuits are well-known. Such patterns can,
for instance, be made by providing a dielectric with a metal layer, and removing part
of the metal layer by means of chemical etching to yield a particular metal circuit
pattern. It will be understood that electric circuits produced in this way are typically
2-dimensional (boards) and do not permit 3-dimensional circuit generation.
[0003] To create 3-dimensional electrical circuits MID-technology (Moulded Interconnect
Device) has been developed [1]. The two main technologies to create MIDs are 2-component
moulding technology and laser direct structuring.
[0004] In the past years, in view of MID and 2K injection moulding applications, different
types of precatalized polymer granules have entered the market. Examples are Vectra
820i Pd of Ticona which comprises Pd particles and more recently Vestodur PBT of Degussa
[2,3] which comprises an iron pigment that, after a chemical release, has the same
catalyzing function as Pd for a subsequent electroless metallization process. Using
such a precatalyzed polymer in combination with a non-precatalyzed polymer in a 2K
injection moulding process, enables the preparation of a product that can be selectively
metallized. In this way, a 3-dimensional electric circuit can be created on a two-component
plastic substrate, such as a substrate comprises one component onto which partly or
completely a second component has been applied, or instance by moulding. Such components
can suitably be thermoplasts. A drawback of the use of two plastics is that these
have different thermomechanical properties which can cause bad adhesion and voids
at the interfaces in the 2-component product. Moreover, moulds for 2-component moulding
are extremely expensive and elaborate to make.
[0005] Another technique for preparing patterns for electric circuits is the socalled Laser
Direct Structuring method wherein a pattern is prepared on an injection moulded one-component
polymer substrate which is for instance made of LCP grade for LDS (supplier Ticona)
that is seeded with a particular metal in the form of a laser sensitive metal complex.
When a laser is selectively applied to the surface of the polymer substrate, the metal
complex present at or near the surface is converted into the corresponding elemental
metal, resulting in a particular pattern of said metal. Subsequently, another layer
of metal can be applied on the metal pattern so obtained. A drawback of this technique
is that the laser equipment and setup is expensive. Moreover, the technique is only
very limited in its 3-dimensional capability. In addition, the method can only create
a metallic pattern on parts of the product that can be illuminated with the laser
and which are not shadowed by another feature on the product. For this reason, also
the creation of metallized through-holes is only possible in a limited way.
[0006] Object of the present invention is to provide relatively inexpensive and simple methods
for 3-dimensional patterns for electric circuits that have a larger dimensional flexibility
than the state-of-the-art methods described above, and that can be applied on one-component
injection moulded parts.
[0007] Surprisingly, it has now been found that that this object can be realised when the
patterns for the electric circuits are prepared by means of a mechanical treatment.
[0008] Accordingly, one aspect of the present invention relates to a method for preparing
a pattern for an electric circuit comprising the steps of:
- (a) providing a substrate onto which a coating has been applied;
- (b) mechanically removing locally the coating to obtain a pattern for an electric
circuit;
- (c) establishing a distribution of particles of a first metal or alloy thereof on
the coating and the pattern as obtained in step (b);
- (d) removing the coating from the substrate; and
- (e) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the particles of the first metal or alloy thereof that are distributed
on the pattern in step (c).
[0009] Suitably, the distribution of the particles of the first metal or alloy thereof on
the coating and the pattern is established in step (c) by means of adsorption of nanoparticles
from a solution.In step (d) the coating can suitably be removed from the substrate
by means of dissolution in a solvent.
[0010] The present invention also provides a method for preparing a pattern for an electric
circuit comprising the steps of:
- (a) providing a substrate onto which a coating has been applied, which substrate comprises
a first metal or alloy thereof;
- (b) mechanically removing locally the coating so as to obtain a pattern for an electric
circuit, thereby exposing at least part of the first metal or alloy thereof present
in the substrate; and
- (c) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the exposed part of the first metal or alloy thereof present in the substrate
as obtained in step (b).
[0011] Another aspect of the invention relates to a method for preparing a pattern for an
electric circuit comprising the steps of:
- (a) providing a substrate onto which a layer of an inhibiting material has been applied;
- (b) mechanically removing locally the layer of the inhibiting material to obtain a
pattern for an electric circuit;
- (c) establishing a distribution of particles of a first metal or alloy thereof on
the layer of the inhibiting material and the pattern as obtained in step (b); and
- (d) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the distribution of the particles of the first metal or alloy thereof as
obtained in step (c), whereby the inhibiting material that is still present on the
substrate after step (b) locally inhibits the second metal or alloy thereof to be
deposited on the first metal or alloy thereof, ensuring that the second metal or alloy
thereof will selectively be deposited on the particles of the first metal or alloy
thereof that are distributed on the pattern obtained in step (b).
[0012] Suitably, the distribution of the particles of the first metal or alloy thereof on
the layer of the inhibiting layer and the pattern in step (c) is established by means
of adsorption from a solution of nanoparticles.
[0013] Further, the present invention also provides a method for preparing a pattern for
an electric circuit comprising the steps of:
- (a) providing a substrate onto which a layer of an inhibiting material has been applied,
which substrate comprises a first metal or alloy thereof;
- (b) mechanically removing locally the layer of the inhibiting material so as to obtain
a pattern for an electric circuit, thereby exposing at least part of the first metal
or alloy thereof present in the substrate;
- (c) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the exposed part of the first metal or alloy thereof present in the substrate
as obtained in step (b), whereby the inhibiting material that is still present on
the substrate after step (b) locally inhibits the second metal or alloy thereof to
be deposited on the first metal or alloy thereof, ensuring that the second metal or
alloy thereof will selectively be deposited on the exposed part of the first metal
or alloy thereof as obtained in step (b).
[0014] In addition, the present invention provides a method for preparing a pattern for
an electric circuit comprising the steps of:
- (a) providing a substrate of which the skin part is more hydrophobic than the internal
part of the substrate;
- (b) mechanically removing locally the skin part to obtain a pattern for an electric
circuit, thereby exposing at least part of the internal part of the substrate;
- (c) establishing a distribution of particles of a first metal or alloy thereof on
the exposed part of the internal part of the substrate as obtained in step (b); and
- (d) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the particles of the first metal or alloy thereof that are distributed
on the pattern in step (c).
[0015] Suitably, the distribution of the particles of the first metal or alloy thereof on
the exposed part of the internal part of the substrate as obtained in step (b) is
established in step (c) by means of adsorption from a solution of nanoparticles.
[0016] Yet another aspect of the present invention relates to a method for preparing a pattern
for an electric circuit comprising the steps of:
- (a) providing a substrate of which the skin part is more hydrophobic than the internal
part of the substrate, which substrate comprises a first metal or alloy thereof;
- (b) mechanically removing locally the skin part so as to obtain a pattern for an electric
circuit, thereby exposing at least part of the first metal or alloy thereof present
in the substrate; and
- (c) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the exposed part of the first metal or alloy thereof present in the substrate
as obtained in step (b).
[0017] Suitably, the distribution of the particles of the first metal or alloy thereof on
the coating and the pattern, on the layer of the inhibiting material and the pattern
or on the exposed part of the internal part of the substrate is established by means
of adsorption from a solution of nanoparticles.
[0018] Suitably, the coating, the layer of inhibiting material or the skin part is mechanically
removed in step (b) by means of milling, scraping, drilling, impressing, embossing
or hot embossing.
[0019] The substrate to be used in accordance with the present invention can suitably comprise
thermoplast materials like liquid crystalline polymer (LCP), polyamide (PA6, PA6,6,
PA4,6, PA12), polyphenylenesulphide (PPS), polyetherimide (PEI), polybutadieneterephtalate
(PBT), syndiotactic polystyrene (SPS), polycarbonate (PC), acrylonitrile-butadiene-styrene
(ABS), PC/ABS-blends, polypropylene (PP), polyethylene (PE), and others.
[0020] Preferably, the substrate comprises LCP, polyamide, PEI, ABS or PC/ABS.
[0021] The substrate can have any thickness depending of course on the use concerned. Suitably,
the thickness can, for instance, be in the range of from 0.5 mm - 10 mm.
[0022] The first metal or alloy thereof to be used in the present invention can suitably
be selected from the group consisting of cobalt, nickel, copper, rhodium, palladium,
platinum, silver and gold.
[0023] Preferably, the first metal is palladium
[0024] In accordance with the present invention the distribution of the first metal or alloy
thereof is such that a layer of the first metal or alloy thereof is obtained. In the
context of the present application, as any skilled person will appreciate, the layer
of the first metal will actually be a coverage of islands of nanoparticles on the
substrate. Hence, such a coverage will usually not constitute an uniform complete
film.
[0025] The second metal or alloy thereof to be used in the present invention can suitably
be selected from the group consisting of copper, nickel, nickel-phosphorous, nickel-boron,
tin, silver, gold, and alloys thereof.
[0026] Preferably, the second metal is copper, nickel-phosphorous or nickel-boron.
[0027] The layer of the second metal or alloy thereof can suitably have a thickness in the
range of from 1 to 30 micrometer, more preferably a thickness in the range of from
3 to 15 micrometer.
The coating to be used in accordance with the present invention can suitably be selected
from the group consisting of poly(styrene), poly(butadiene), poly(propylene), poly(ethylene),
poly(carbonate), poly(etherether ketone), poly(vinylchloride), poly(vinylidene chloride),
poly(vinylidene fluoride), poly(tetrafluoroethylene), poly(acrylate), poly(phenylene
sulfide), poly(sulfone), poly(ethersulfone), poly(ethyleneterephthalate), poly(ethylenenaphthalate),
poly(butylterephthalate), poly(caprolactone), poly(ester), poly(vinyl alcohol), poly(vinyl
ether), poly(siloxane), poly(acrylonitrile), poly(caprolactam), poly(amide), parylene,
poly(naphthalene), poly(imides), acrylates, epoxides, epoxies, epoxy-amines, vinyl
monomers, phenolic resins, wax, grease and melamines.
[0028] The coating can suitably have a thickness in the range of 1 micrometer to 2 mm. Preferably,
the coating has a thickness in the range of from 0.3 to 1 mm.
[0029] The inhibiting material to be used in accordance with the present invention suitably
comprises any material that is known to inhibit or stabilise electroless deposition
processes, e.g. heavy metal ions, organic and inorganic sulphur-, selenium or tellur-
containing compounds, oxygen containing compounds and aliphatic and unsatisfied organic
compounds [4Preferably, the inhibiting material comprises thiourea, dodecanethiol,
dipyridil, lead acetate, maleic acid or 2-mercaptobenzothiazole. Most preferably,
the inhibiting material comprises 2-mercaptobenzothiazole or thiourea.
[0030] The layer of inhibiting material can suitably be either an incomplete adsorbed surface
coverage, adsorbed monolayer or a multilayer.
[0031] When use is made of a substrate of which the skin part is more hydrophobic than the
internal part of the substrate, such skin part can suitably have a thickness in the
range of from 1 to 300 micrometer. Suitably, such a skin part has a contact angle
for water of at least 30 degrees higher than the internal part of the substrate. Preferably,
such a skin part has a contact angle for water of at least 50 degrees higher than
the internal part of the substrate.
[0032] In an electroless plating process use is made of the principle that a metal which
is available in ionic form in solution can be reduced by a reducing agent into its
metallic form on a suitable catalytic surface. Moreover, the metal itself should also
be catalytic to the reduction reaction, rendering the process autocatalytic as such
For general descriptions on electroless plating processes reference can, for instance,
be made to
Electroless Plating Fundamentals & Applications, edited by Glenn O. Mallory and Juan
B. Hajdu, New York (1990) [4].
[0033] In the electroless plating process suitably use is made of a solution containing
the second metal to be deposited on the distribution of the first metal. Suitable
metal-containing solutions include, but are not limited to, solutions water-based
solutions of copper salts (e.g. copper sulphate) and formaldehyde as reducing agent,
and water based solution of nickel sulphate with hypophosphite, dimethylaminoborane
or sodium borohydride as reducing agent.
[0034] The present invention also relates to an electric circuit comprising a pattern as
prepared by means of the method according to the present invention.
[0035] In addition, the present invention relates to device comprising an electric device
in accordance with the present invention. Suitable examples of such devices include
but are not limited to interconnection parts or sensors for use in vehicles, computers,
digital cameras and mobile phones.
Examples
Example 1
[0036] A synthetic polymer substrate made of PA46 stanyl, with dimensions (Weight x Height
x Thickness) 65 mm x 70 mm x 4 mm was selectively plated with copper, using the following
sequence of process steps:
At first the substrate was coated with an inhibitor by immersing the substrate during
a couple of minutes in a solution of 30 g/l thiourea respectively 30 g/l 2-mercaptobenzothiazole
(2-MBT). After immersion the sample was rinsed with (demineralised) water. The coating
so obtained was locally removed by milling a pattern with different depths and track
widths. Subsequently, a distribution of a palladium catalyst was established on the
coating using the commercially available colloidal catalyzation process Cu9040-Cu9050
of Cookson Electronics. The substrate so obtained was rinsed during 1 minute in (demineralised)
water. Then, a layer of copper was deposited on the substrate during 5 minutes at
40°C using the commercially available electroless copper bath Cu9070 of Cookson Electronics.
Metal deposition occurred solely in the milled tracks.
Example 2
[0037] A synthetic polymer substrate made of PA46 stanyl, with dimensions (Weight x Height
x Thickness) 65 mm x 70 mm x 4 mm was selectively plated with nickel, using the following
sequence of process steps: At first the substrate was coated with an inhibitor by
immersing the substrate during a couple of minutes in a solution of 30 g/l 2-mercaptobenzothiazole
(2-MBT). After immersion, the substrate so obtained was rinsed with (demineralised)
water. The coating so obtained was locally removed by milling to obtain a pattern
with different depths and track widths. Subsequently, a distribution of palladium
catalyst was established, using an ionic catalyzation process. In order to establish
this, the substrate was immersed during 2 minutes in a solution of 10 g/l SnCl2 and
40 ml/l HCl. After immersion, the substrate so obtained was rinsed with (demineralised)
water during 1 minute. After rinsing, the substrate was immersed during 1 minute in
a solution of 0.25 g/l PdCl2 and 2.5 ml/l HCl at room temperature. The substrate so
obtained was then rinsed during 1 minute in (demineralised) water. Subsequently, a
layer of nickel wad deposited on the substrate during 5 minutes at 80°C using the
commercially available electroless nickel bath EN439 of Cookson Electronics.
[0038] Metal deposition occurred solely in the milled tracks.
Example 3
[0039] A synthetic polymer substrate made of PA46 stanyl, with dimensions (Weight x Height
x Thickness) 65 mm x 70 mm x 4 mm was selectively plated with nickel, using the following
sequence of process steps: At first the substrate was coated with a inhibitor by immersing
the substrate during a couple of minutes in a solution of 30 g/l thiourea respectively
30 g/l 2-mercaptobenzothiazole (2-MBT).
[0040] After immersion, the substrate was rinsed with (demineralised) water. The coating
so obtained was locally impressed with a metal stamp to obtain a pattern with different
depths and track widths. Subsequently, a distribution of palladium catalyst was established,
using anionic catalyzation process. In order to establish this, the substrate was
immersed during 2 minutes in a solution of 10 g/l SnCl2 and 40 ml/l HCl. After immersion,
the sample was rinsed with (demineralised) water during 1 minute. After rinsing, the
substrate so obtained was immersed during 1 minute in a solution of 0.25 g/l PdCl2
and 2.5 ml/l HCl at room temperature. Then, the substrate was rinsed during 1 minute
in (demineralised) water. Subsequently, a layer of nickel was deposition on the substrate
during 5 minutes at 60°C in an electroless nickel bath having a pH value of 6. 1 and
containing 24 g/l NiCl2 ·6H2O; -30 g/l C3H6O3 (, lactic acid); 15 g/l CH3COONa (sodium
acetate); and 2.5 g/l dimethylammoniumborane. Metal deposition occurred solely in
the track created by stamping.
Example 4
[0041] A synthetic substrate made of Ticona Vectra E820i Pd, which was precatalyzed with
a distribution of a palladium catalyst, with dimensions (Weight x Height x Thickness)
65 mm x 70 mm x 4 mm was selectively plated with copper, using the following sequence
of process steps:
At the surface of the substrate was the palladium catalyst was locally exposed by
milling to obtain a pattern with different depths and track widths.
[0042] Subsequently, a layer of nickel was deposited on the substrate during 20 minutes
at 48°C using the commercially available electroless copper bath Cu9070 of Cookson
Electronics. Metal deposition occurred solely in the milled tracks.
Example 5
[0043] A synthetic substrate made of Ticona Vectra E820i Pd, which was precatalyzed with
a distribution of a palladium catalyst, with dimensions (Weight x Height x Thickness)
65 mm x 70 mm x 4 mm was selectively plated with copper, sung the following sequence
of process steps:
At the surface of the substrate the palladium catalyst was locally exposed by milling
to obtain a pattern with different depths and track widths. Subsequently, a layer
of nickel was deposited at 60°C in a similar electroless nickel bath as used in Example
3.
Example 6
[0044] A synthetic substrate made of Ticona Vectra E820i, with dimensions (Weight x Height
x Thickness) 65 mm x 70 mm x 4 mm was selectively plated with copper, using the following
sequence of process step: At first the substrate was coated with a inhibitor by immersing
the substrate during a couple of minutes in a solution of 30 ml/l dodecanethiol respectively
30 g/l 2-mercaptobenzothiazole (2-MBT).After immersion, the substrate obtained was
rinsed with (demineralised) water. Subsequently, the coating was locally removed by
scraping to obtain a pattern with different depths and track widths. Then, a distribution
of a palladium catalyst was established on the substrate, using the commercially available
colloidal catalyzation process Cu9040-Cu9050 of Cookson Electronics. The substrate
so obtained was then rinsed during 1 minute in (demineralised) water. Thereafter,
a layer of copper was deposited on the substrate during 5 minutes at 40°C in the commercially
available electroless copper bath Cu9070 of Cookson Electronics. Metal deposition
occurred solely in the milled tracks.
Example 7
[0045] A synthetic substrate which was made of Ticona Vectra E820i, with dimensions (Weight
x Height x Thickness) 65 mm x 70 mm x 4 mm was selectively plated with nickel, using
the following sequence of process steps: At first the substrate was coated with a
inhibitor by immersing the substrate during a couple of minutes in a solution of 30
ml/l dodecanthiol respectively 30 g/l 2-mercaptobenzothiazole (2-MBT).After immersion,
the substrate was rinsed with (demineralised) water. Subsequently, he coating so obtained
was locally removed by milling to obtain a pattern with different depths and track
widths. Then, a distribution of a palladium catalyst was established on the substrate
using an ionic catalyzation process. In order to establish this, the substrate was
immersed during 2 minutes in a solution of 10 g/l SnCl2 and 40 ml/l HCl. After immersion,
the substrate so obtained sample was rinsed with (demineralised) water during 1 minute.
After rinsing, the substrate was immersed during 1 minute in a solution of 0.25 g/l
PdCl2 and 2.5 ml/l HCl at room temperature. The substrate was subsequently rinsed
during 1 minute in (demineralised) water. Then, a layer of nickel was deposited on
the substrate during 5 minutes at 80°C using the commercially available electroless
nickel bath EN439 of Cookson Electronics. Metal deposition occurred solely in the
milled tracks.
Example 8
[0046] A synthetic substrate which was made of Ticona Vectra E820i, with dimensions (Weight
x Height x Thickness) 65 mm x 70 mm x 4 mm was selectively plated with nickel, using
the following sequence of process steps: At first the substrate was coated with a
inhibitor by immersing the substrate during a couple of minutes in a solution of 30
ml/l dodecanthiol respectively 30 g/l 2-mercaptobenzothiazole (2-MBT).After immersion,
the substrate so obtained was rinsed with (demineralised) water. Then, the coating
so obtained was locally removed by scraping to obtain a pattern with different depths
and track widths. Subsequently, a distribution of a palladium catalyst was established
on the substrate using a ionic catalyzation process. In order to establish this, the
substrate was immersed during 2 minutes in a solution of 10 g/l SnCl2 and 40 ml/l
HCl. After immersion, the substrate was rinsed with (demineralised) water during 1
minute. After rinsing, the substrate was immersed during 1 minute in a solution of
0.25 g/l PdCl2 and 2.5 ml/l HCl at room temperature. The substrate so obtained was
then rinsed during 1 minute in (demineralised) water. Then, a layer of nickel was
deposited on the substrate during 5 minutes at 60°C using a similar electroless nickel
bath as described in Example 3 Metal deposition occurred solely in the milled tracks.
Example 9
[0047] A synthetic substrate made of PA46 Stanyl, was coated with a commercially available
polyurethane coating. The coating so obtained was locally removed by milling to obtain
a pattern with different depths and track widths.
[0048] In the next step a distribution of a palladium catalyst was established on the surface
of a first sample of the substrate using an ionic catalyzation process, whereas on
a second sample of the substrate a distribution of the palladium catalyst was established
by means of a colloidal catalyzation process.
[0049] In the ionic catalyzation process the substrate was immersed in a solution of 10
g/l SnCl2 and 40 ml/l HCl, for 2 minutes at room temperature, whereafter thye substrate
so obtained was rinsed with (demineralised) water. The substrate so obtained was then
immersed in a solution of 0.25 g/l PdCl2 and 2.5 ml/l HCl, for 1 minute at room temperature.
The substrate so obtained was then rinsed with (demineralised) water. In the colloidal
catalyzation process use was made of the commercially available colloidal catalyzation
process of, Cookson Electronics, wherein the substrate was immersed during 2 minutes
in the Cu9040 solution at room temperature. Subsequently, the substrate was rinsed
with (demineralised) water. The substrate so obtained was then immersed during 2 minutes
in the Cu9050 solution at 40°C, and subsequently rinsed with (demineralised) water.
After the distribution of the palladium catalyst on the surface of the substrate was
established, the coating was removed by immersing the substrate in a dichloromethane.
[0050] On one sample of the substrate so obtained a copper layer was deposited on the substrate
by means of a commercially available electroless copper bath Cu9070 of Cookson Eletronics,
whereas on another sample of the substrate so obtained a nickel layer was deposited
on the substrate using a similar electroless nickel bath as described in Example 3.
[0051] The surface of the substrates so obtained which had been coated contained no metal
depositions, and the part were the coating was removed was plated either with copper
or nickel.
Example 10
[0052] A synthetic substrate made of Ticona Vectra E820i Pd, which was precatalyzed with
a palladium catalyst, was coated with a commercially available epoxy coating. The
coating so obtained was locally removed by milling to obtain a pattern with different
depths and track widths. Subsequently, the coating was removed by immersing the substrate
in dichloromethane.
[0053] At the surface of a sample of the substrate so obtained was then a layer of copper
deposited using the eletroless copper bath Cu9070 as described in Example 9, whereas
at the surface of another sample of the substrate so obtained a layer of nickel was
deposited using electroless nickel bath as described in Example 3.
[0054] The surface of the samples of the substrate which had been coated contained no metal
deposition, and the part were the coating was removed was plated either with copper
or nickel.
References
1. A method for preparing a pattern for an electric circuit comprising the steps of:
(a) providing a substrate onto which a coating has been applied;
(b) mechanically removing locally the coating to obtain a pattern for an electric
circuit;
(c) establishing a distribution of particles of a first metal or alloy thereof on
the coating and the pattern as obtained in step (b);
(d) removing the coating from the substrate; and
(e) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the particles of the first metal or alloy thereof that are distributed
on the pattern in step (c).
2. A method for preparing a pattern for an electric circuit comprising the steps of:
(a) providing a substrate onto which a coating has been applied, which substrate comprises
a first metal or alloy thereof;
(b) mechanically removing locally the coating so as to obtain a pattern for an electric
circuit, thereby exposing at least part of the first metal or alloy thereof present
in the substrate; and
(c) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the exposed part of the first metal or alloy thereof present in the substrate
as obtained in step (b).
3. A method for preparing a pattern for an electric circuit comprising the steps of:
(a) providing a substrate onto which a layer of an inhibiting material has been applied;
(b) mechanically removing locally the layer of the inhibiting material to obtain a
pattern for an electric circuit;
(c) establishing a distribution of particles of a first metal or alloy thereof on
the layer of the inhibiting material and the pattern as obtained in step (b); and
(d) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the distribution of the particles of the first metal or alloy thereof as
obtained in step (c), whereby the inhibiting material that is still present on the
substrate after step (b) locally inhibits the second metal or alloy thereof to be
deposited on the first metal or alloy thereof, ensuring that the second metal or alloy
thereof will selectively be deposited on the particles of the first metal or alloy
thereof that are distributed on the pattern obtained in step (b).
4. A method for preparing a pattern for an electric circuit comprising the steps of:
(a) providing a substrate onto which a layer of an inhibiting material has been applied,
which substrate comprises a first metal or alloy thereof;
(b) mechanically removing locally the layer of the inhibiting material so as to obtain
a pattern for an electric circuit, thereby exposing at least part of the first metal
or alloy thereof present in the substrate;
(c) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the exposed part of the first metal or alloy thereof present in the substrate
as obtained in step (b), whereby the inhibiting material that is still present on
the substrate after step (b) locally inhibits the second metal or alloy thereof to
be deposited on the first metal or alloy thereof, ensuring that the second metal or
alloy thereof will selectively be deposited on the exposed part of the first metal
or alloy thereof as obtained in step (b).
5. A method for preparing a pattern for an electric circuit comprising the steps of:
(a) providing a substrate of which the skin part is more hydrophobic than the internal
part of the substrate;
(b) mechanically removing locally the skin part to obtain a pattern for an electric
circuit, thereby exposing at least part of the internal part of the substrate;
(c) establishing a distribution of particles of a first metal or alloy thereof on
the exposed part of the internal part of the substrate as obtained in step (b); and
(d) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the particles of the first metal or alloy thereof that are distributed
on the pattern in step (c).
6. A method for preparing a pattern for an electric circuit comprising the steps of:
(a) providing a substrate of which the skin part is more hydrophobic than the internal
part of the substrate, which substrate comprises a first metal or alloy thereof;
(b) mechanically removing locally the skin part so as to obtain a pattern for an electric
circuit, thereby exposing at least part of the first metal or alloy thereof present
in the substrate; and
(c) depositing by means of an electroless process a layer of a second metal or alloy
thereof on the exposed part of the first metal or alloy thereof present in the substrate
as obtained in step (b).
7. A method according to claim 1, 3 or 5, wherein in step (c) the distribution of the
particles of the first metal or alloy thereof is established by means of adsorption
of nanoparticles or ions from a solution.
8. A method according any one of claims 1-7, wherein in step (b) the coating, the layer
of inhibiting material or the skin part is mechanically removed by means of milling,
scraping, drilling, impressing, embossing or hot embossing.
9. A method according to any one of claims 1-8, wherein the substrate comprises a thermoplast
product.
10. A method according to claim 9, wherein the substrate comprises LCP, polyamide, PEI,
ABS or PC/ABS.
11. A method according to any one of claims 1-10, wherein the first metal is selected
from the group consisting of cobalt, nickel, copper, rhodium, palladium, platinum,
silver and gold.
12. A method according to claim 11, wherein the first metal is palladium.
13. A method according to any one of claims 1-12, wherein the second metal is selected
from the group consisting of copper, nickel, nickel-phosphorous, nickel-boron, tin,
silver, and gold or alloys thereof.
14. A method according to claim 13, wherein the second metal comprises copper, nickel-phosphorous
or nickel-boron.
15. A method according to any one of claims 1, 2 or 7-15, wherein the coating is selected
from the group consisting of poly(styrene), poly(butadiene), poly(propylene), poly(ethylene),
poly(carbonate), poly(etherether ketone), poly(vinylchloride), poly(vinylidene chloride),
poly(vinylidene fluoride), poly(tetrafluoroethylene), poly(acrylate), poly(phenylene
sulfide), poly(sulfone), poly(ethersulfone), poly(ethyleneterephthalate), poly(ethylenenaphthalate),
poly(butylterephthalate), poly(caprolactone), poly(ester), poly(vinyl alcohol), poly(vinyl
ether), poly(siloxane), poly(acrylonitrile), poly(caprolactam), poly(amide), parylene,
poly(naphthalene), poly(imides), acrylates, epoxides, epoxies, epoxy-amines, vinyl
monomers, phenolic resins, wax, grease and melamines.
16. A method according to any one of claims 3, 4 or 7-15, wherein the inhibiting material
comprises heavy metal ions, organic and inorganic sulphur-, selenium or tellur- containing
compounds, oxygen containing compounds and aliphatic and unsatisfied organic compounds.
17. A method according to claim 16, wherein the inhibiting material comprises 2-mercaptobenzothiazole
or thiourea.
18. A method according to any one of claim 1 or 7-15, wherein in step (d) the coating
is removed from the substrate by means of dissolution in a solvent.
19. An electric circuit comprising a pattern as prepared by means of a method according
to any one of claims 1-18.
20. A device comprising an electric device according to claim 19.